中文摘要：

以2004年以前自愿采纳国际财务报告准则（IFR S）且具有独特制度背景的欧盟15国上市公司为研究样本,对这类公司在2005年欧盟强制所有上市公司采纳IFRS以后盈余质量是否有了进一步提高进行了研究。研究发现,2004年以前自愿采纳IFR S的公司更少地进行微利盈余管理,具有更低的截面操纵性应计利润绝对值,这说明欧盟强制采纳IFR S后显著提高了自愿采纳IFRS公司的盈余质量。上述结论表明,IFRS这一制度安排由国家法律强制执行比纯粹依靠公司自我执行效果更优,这为尚未采纳或正在考虑采纳IFRS的国家提供了一条关于IFRS采纳方式的现实路径。

英文摘要：

Using the voluntary International Financial Reporting Standards（IFRS） adoption companies before 2004 in the European Union（EU） 15 member states that have unique institutional settings as the research sample,this study investigates whether earnings quality of voluntary IFRS adoption companies is further improved after mandatory IFRS adoption in the EU starting from Jan.1st 2005.The authors find that voluntary IFRS adoption companies have less involved in small profit management and lower magnitude of absolute discretionary accruals after mandatory IFRS adoption in the EU,which indicates that earnings quality of voluntary IFRS adoption companies is further improved after mandatory IFRS adoption in the EU.The results are robust to a number of sensitivity tests.The above result indicates that the positive IFRS adoption effect of statutory enforcement by country law is higher than just relied on self-enforcement by company.Therefore,this provides an effective path regarding IFRS adoption for the rest countries which is about to or considering adopting IFRS.